Abstract: The gas hydrogen permeation process of Zr-Sn-Nb alloy sheet was studied, and the effects of hydrogen permeation time and annealing time on hydrogen content and its distribution were investigated. The results show that with the increase of hydrogen infiltration time, hydride content increases and the hydrides appear to aggregate, form a winding and growing strip structure, and finally gradually present a fine network distribution. During the annealing process, the hydrogen atoms spread from the outer surface to the center of the wall, and the two ends spread to the middle. The higher the hydride content, the longer the annealing time, the more fully the hydride diffusion, the strip hydrides decompose into several fine hydrides and dispersed evenly in the zirconium matrix. The exponential function was used to fit the law of hydrogen content-hydrogen infiltration time, and the corresponding relationship between the quantitative hydrogen infiltration process and hydrogen content of Zr-Sn-Nb alloy was obtained.

Key words: Zr-Sn-Nb alloy, gas hydrogen infiltration, annealing after hydrogen infiltration, hydride